The "SAS Guide to the SQL Procedure" was a good primer in my experience.
It's short and has many examples.
The v9 guide is online here
SAS(R) 9.1 SQL Procedure User's Guide
DDS Data Extraction
From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of Mike
Sent: Tuesday, December 07, 2004 10:27 AM
Subject: SQL for Normal People
One of our programmers is well above the "SQL for Dummies" level, but found
Joe Celko's "SQL for Smarties: Advanced SQL Programming" to be a little too
daunting in places (as do I, for that matter). Anybody have any good book
recommendations for something in between? Note that the interest is in SQL
in general, not necessarily that which is SAS-specific.